The effects of selective retrograde revascularization of the coronary vein (SRRCV) and selective coronary vein occlusion (SVC) on both normal and ischemic myocardium were evaluated in a canine model (10 animals). The distribution of myocardial blood flow (MBF) and multiple hemodynamic parameters were measured before and after occlusion of the main left anterior descending coronary artery (LADCA) and after 5 minutes and 30 minutes of SSRCV to the great cardiac vein. SCVO decreases mean MBF in H and L myocardium with increased distribution to the endocardium. This decrease is significantly greater in L (distal) compared to (H) proximal myocardium. SRRCV to normally perfused myocardium in H did not significantly change MBF; however, MBF remained less in H than in L myocardium. SRRCV to acutely ischemic myocardium L restored less than 50 per cent of the decrease in MBF. SRRCV does not appear to greatly enhance MBF to ischemic areas and may significantly reduce MBF on a basis of venous occlusion alone.